Safe-T-Stain from
Philtec consists primarily of metal salts, in an electrolyte which
have been used extensively to stain the more n-type regions on the
silicon wafer. This characteristic holds consistent with the p on p+
being darkened. Repeatable results are achieved by control of light
intensity and staining time. Five compositions are available to
permit selection of the most appropriate stain.
Overstained regions often require no refinishing; they are merely wiped with a
dampener paper towel and re-stained. The chemical composition of this
stain does not necessitate extraordinary safety precautions during
it's use. Minimal experience and technique are needed to stain
junctions with Philtec Safe-T-Stain, because a unique stain
composition is available for most junction impurity concentration ranges.
DSS-1
Solution
colour Yellow
Formulated to be
used on material which has heavily doped n & p layers. This stain
has the least amount of activator and salts in it, making possible
gradual delineation, and avoiding overstaining.
SOLD OUT
DSS-2
Solution colour Red
For heavily doped
layer with somewhat lighter doping of opposite polarity.
DSS-3
Solution
colour Orange SOLD OUT
This stain has a
strength of activator and salts that suits a wide range of applications.
DSS-4
Solution colour Green
Contains more
activator, which is useful for materials, where other stains would be
to slow to bring out the layers.
SOLD OUT
DSS-5
Solution colour Blue
Has the strongest
concentration of activator & salts, for use on very lightly doped areas.
Note: For
applications where wafers will be going through further diffusions,
the stain can be removed by using Ammonium Persulfate (NH4) S2O2.
SOLD OUT
Features
:-
-
Enables
observation of the staining through a microscope, whilst it is taking
place, without damaging the optics.
-
Sharply and
rapidly delineates diffused abd epitaxial layers in material with a
wide variety of deposits, concentrations, and layer depths.
-
Does not etch out
layers to be measured, most noticeable when measuring thin layers.
-
Minimally effects
oxide on the surface of a wafer when it is present.
-
Eliminates the
need for a fume hood, and does not corrode the surrounding equipment.
